#lang minimart

(require racket/set)
(require (only-in racket/string string-trim))
(require "../drivers/tcp.rkt")
(require "../demand-matcher.rkt")

(define (spawn-session them us)
  (define user (gensym 'user))
  (define remote-detector (project-pubs #:meta-level 1 (?!)))
  (define peer-detector (project-pubs `(,(?!) says ,?)))
  (define (send-to-remote fmt . vs)
    (send #:meta-level 1 (tcp-channel us them (string->bytes/utf-8 (apply format fmt vs)))))
  (define (say who fmt . vs)
    (unless (equal? who user) (send-to-remote "~a ~a\n" who (apply format fmt vs))))
  (list (send-to-remote "Welcome, ~a.\n" user)
	(spawn (lambda (e old-peers)
		 (log-info "~a: ~v --> ~v" user e old-peers)
		 (match e
		   [(message (tcp-channel _ _ bs) 1 #f)
		    (transition old-peers
				(send `(,user says ,(string-trim (bytes->string/utf-8 bs)))))]
		   [(message `(,who says ,what) 0 #f)
		    (transition old-peers (say who "says: ~a" what))]
		   [(routing-update g)
		    (define new-peers (gestalt-project/single g peer-detector))
		    (transition
		     new-peers
		     (list (when (matcher-empty? (gestalt-project g remote-detector)) (quit))
			   (for/list [(who (set-subtract new-peers old-peers))]
			     (say who "arrived."))
			   (for/list [(who (set-subtract old-peers new-peers))]
			     (say who "departed."))))]
		   [#f #f]))
	       (set)
	       (gestalt-union (sub `(,? says ,?))
			      (sub `(,? says ,?) #:level 1)
			      (pub `(,user says ,?))
			      (sub (tcp-channel them us ?) #:meta-level 1)
			      (sub (tcp-channel them us ?) #:meta-level 1 #:level 1)
			      (pub (tcp-channel us them ?) #:meta-level 1)))))

(spawn-tcp-driver)
(spawn-world
 (spawn-demand-matcher (tcp-channel (?! (tcp-address ? ?)) (?! (tcp-listener 5999)) ?)
		       #:meta-level 1
		       spawn-session))